Enter your information to understand your insulin levels.

The History of Insulin

Insulin was famously discovered in 1921 by Canadian surgeon Frederick Banting and medical student Charles Best, working together in a small laboratory at the University of Toronto under the broader supervision of physiologist John Macleod, with biochemist James Collip later joining the team to help purify the extract sufficiently for safe human use. In January 1922, the team successfully treated fourteen-year-old diabetic patient Leonard Thompson with their purified pancreatic extract, dramatically improving his condition and marking the very first successful use of insulin therapy in human medical history. This extraordinary achievement earned Banting and Macleod the 1923 Nobel Prize in Physiology or Medicine, a decision that famously proved controversial since Banting felt Best deserved equal recognition, prompting him to voluntarily and generously share his own prize money with his younger research partner instead.

What Insulin Actually Is

Insulin is a hormone produced by specialized beta cells located within the pancreas, released directly into the bloodstream in response to rising blood glucose levels after eating a meal containing carbohydrates or other nutrients. Its primary job is signaling cells throughout the body, particularly in muscle, fat, and liver tissue, to absorb glucose from the bloodstream and either use it immediately for energy or store it away for later use, effectively keeping blood sugar levels within a tightly regulated, healthy range. When the pancreas cannot produce enough insulin, as happens in type 1 diabetes, or when the body's tissues become resistant to insulin's normal signaling effects, as happens in type 2 diabetes, blood glucose levels can rise to genuinely dangerous levels over time if left untreated.

How Insulin Is Measured

Insulin is measured from a blood sample using immunoassay technology, a method whose origins trace directly back to physicist Rosalyn Yalow and physician Solomon Berson, who developed radioimmunoassay technology specifically to measure insulin's remarkably tiny circulating concentrations for the very first time in the 1950s. This groundbreaking achievement, which eventually earned Yalow the 1977 Nobel Prize in Physiology or Medicine, made it possible to detect hormone concentrations far too small for any previous laboratory technique to reliably measure at all. Modern laboratories now use considerably safer, non-radioactive immunoassay methods built directly upon that same original scientific foundation, routinely measuring fasting insulin alongside glucose to help evaluate insulin resistance and broader metabolic health.

Scientists Behind the Science

Frederick Banting and Charles Best's determined 1921 discovery transformed type 1 diabetes from an almost universally fatal childhood diagnosis into a genuinely manageable chronic condition, arguably one of the single most consequential medical breakthroughs of the entire twentieth century. Rosalyn Yalow's later radioimmunoassay work then made it possible to actually measure insulin precisely within the bloodstream, an achievement every bit as scientifically significant as the original discovery itself, since it finally allowed doctors to directly study and monitor the hormone's behavior in real, living patients. Together, spanning more than three decades of relentless scientific progress, their combined contributions built the entire modern foundation of diabetes diagnosis, treatment, and ongoing clinical management used worldwide today.